Argosy: a large (??)
Agreed!
We know a song about that, don't we boys and girls? "And the Argosy too, with a pound or two..", from the renowned Mess bar refrain, 'See Them Fly By'.
The exceptions to AMPANC's cunning plan were many of course, mainly those with some commercial pretensions. Britannia, Comet, even the Argosy. The former could otherwise have become the Bristol Bristol!
As to Valetta, the present Valletta might be the 'incorrect' spelling :-
https://en.wikisource.org/wiki/Letit...,_1837/Valetta